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EP1060296A1 - Specific cathode, used for preparing an alkaline metal chlorate and method for making same - Google Patents

Specific cathode, used for preparing an alkaline metal chlorate and method for making same

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Publication number
EP1060296A1
EP1060296A1 EP99903733A EP99903733A EP1060296A1 EP 1060296 A1 EP1060296 A1 EP 1060296A1 EP 99903733 A EP99903733 A EP 99903733A EP 99903733 A EP99903733 A EP 99903733A EP 1060296 A1 EP1060296 A1 EP 1060296A1
Authority
EP
European Patent Office
Prior art keywords
titanium
ruthenium
cathode according
zirconium
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP99903733A
Other languages
German (de)
French (fr)
Other versions
EP1060296B1 (en
Inventor
Françoise Andolfatto
François Delmas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Arkema France SA
Original Assignee
Atofina SA
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Publication of EP1060296A1 publication Critical patent/EP1060296A1/en
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/093—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/02—Hydrogen or oxygen
    • C25B1/04—Hydrogen or oxygen by electrolysis of water
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B15/00—Operating or servicing cells
    • C25B15/02—Process control or regulation
    • C25B15/021—Process control or regulation of heating or cooling

Definitions

  • the present invention relates to a cathode which can be used for the preparation of an alkali metal chlorate by electrolysis of the corresponding chloride, and to the process for its production.
  • cathodes While the activation of cathodes for the electrolytic synthesis of sodium chlorate has been the subject of numerous studies, on the other hand very few studies have been devoted to obtaining specific cathodes. However, it is known that in the electrolytic preparation of sodium chlorate, in addition to the reactions leading to the final product, there are many side reactions. Thus at the cathode, in addition to the reduction of water to hydrogen, there takes place a reduction reaction of the hypochlorite ion.
  • sodium chlorate is manufactured in electrolytic cells, each of which comprises several mild steel cathodes and several titanium anodes coated with ruthenium oxide. They are generally supplied with an electrolytic solution consisting of approximately 1 00 g / l of sodium chloride, approximately 600 g / l of sodium chlorate and sodium dichromate in an amount between 2 and 5 g / l.
  • a cathode whose substrate is a plate of titanium, zirconium, niobium or an alloy essentially constituted by a combination of these metals and to which is applied a layer of metal oxide, essentially constituted by an oxide of a or several metals chosen from ruthenium, rhodium, palladium, osmium, iridium and platinum and optionally an oxide from one or more metals chosen from calcium, magnesium, strontium, barium, zinc , the 2 chromium, molybdenum, tungsten, selenium and tellurium, was disclosed in French patent FR 2 31 1 1 08.
  • This specific cathode comprises a substrate made of an element chosen from the group formed from titanium, nickel, tantalum, zirconium, nobium and their alloys, coated with an intermediate layer of mixed oxide based on titanium and ruthenium and a outer layer of metal oxides comprising titanium, zirconium and ruthenium.
  • the intermediate layer contains a mixed oxide of titanium and ruthenium.
  • the outer layer of metal oxides contains titanium, zirconium and ruthenium.
  • the outer layer consists essentially of ZrTi ⁇ 4 accompanied by Ru ⁇ 2 and possibly Zr ⁇ 2 and / or Ti ⁇ 2-
  • titanium or nickel or titanium or nickel alloys Even better, we prefer to use titanium.
  • the ruthenium / titanium molar ratio in the intermediate layer is preferably between 0.4 and 2.4.
  • the zirconium / titanium molar ratio in the outer layer is generally between 0.25 and 9, preferably between 0.5 and 2.
  • the ruthenium in the outer layer represents between 0.1 and 10 mol%, preferably between 0.1 and 5 mol% relative to the metals used in the composition of this layer.
  • Another object of the invention is the process for preparing the specific cathode, comprising the following steps: a) pretreatment of a substrate to impart surface roughness characteristics, b) coating of the pretreated substrate using a solution A essentially containing titanium and ruthenium, followed by drying, then calcination of the substrate thus coated, C) coating of the substrate obtained in (b) using a solution B comprising titanium, zirconium and ruthenium, followed by drying, and calcination of the substrate.
  • the pretreatment generally consists in subjecting the substrate, either to a sandblasting followed by an acid washing, or to a pickling using an aqueous solution of oxalic acid, hydrofluoric acid, a mixture of hydrofluoric acid and nitric acid, mixture of hydrofluoric acid and glycerol, mixture of hydrofluoric acid, nitric acid and glycerol or mixture of hydrofluoric acid, d 'nitric acid and hydrogen peroxide, followed by one or more washing (s) with degassed demineralized water.
  • the substrate may be in the form of a solid plate, perforated plate, expanded metal or cathode basket made from the expanded or perforated metal.
  • Solution A is generally prepared by reacting at room temperature and with stirring, essentially a mineral or organic salt of titanium and ruthenium with water or in an organic solvent, optionally in the presence of a chelating agent. The temperature can be brought slightly above the ambient to facilitate the dissolution of the salts.
  • a mineral or organic salt of titanium and ruthenium is reacted with water or in an organic solvent, optionally in the presence of a chelating agent.
  • Titanium and ruthenium are preferably present in solution A in a concentration equivalent to each of 0.5 to 10 mole / l.
  • Solution B is generally prepared by reacting, at room temperature and with stirring, an inorganic or organic salt of titanium, zirconium, ruthenium and optionally other metals with water or in an organic solvent, optionally in presence of a chelating agent. When the reaction is exothermic, an ice bath is used to cool the reaction medium.
  • a mineral or organic salt of titanium, zirconium and ruthenium is reacted with water or in an organic solvent, optionally in the presence of a chelating agent.
  • the preferred titanium and ruthenium salts are chlorides, oxychlorides, nitraters, oxynitrates, sulfates and alkoxides.
  • ruthenium chlorides, titanium chlorides and titanium oxychlorides are used.
  • zirconium salts it is possible to use chlorides, sulfates, zirconyl chlorides, zirconyl nitrates, alkoxides such as butyl zirconate.
  • Zirconium and zirconyl chlorides are particularly preferred.
  • organic solvent there may be mentioned light alcohols, preferably isopropanol and ethanol, and better still isopropanol and absolute ethanol.
  • the metal salt is zirconium chloride
  • absolute ethanol or absolute isopropanol is used as the solvent.
  • Titanium and zirconium are generally present in the solution
  • Solution A can be deposited on the pretreated substrate using different techniques such as sol-gel, electrochemical deposition, galvanic plating, spraying or coating.
  • the pretreated substrate is coated with solution A, for example using a brush.
  • the substrate thus coated is then dried in air and / or in an oven at a temperature below 150 ° C.
  • the substrate is calcined in air at a temperature between 300 and 600 ° C and preferably between 450 and 550 ° C for a period ranging from 10 minutes to 2 hours.
  • step (c) of the process according to the present invention the same deposition techniques can be used as well as the same operating conditions for drying and calcination as step (b) except that the deposition is carried out with solution B.
  • CVD chemical vapor deposition
  • PVD physical vapor deposition
  • plasma spraying are also suitable for coating the pretreated substrate with an intermediate layer and an outer layer.
  • Solution A can be deposited both on one side of the pretreated substrate and on both sides. You can also file the 5 solution B on both sides of the substrate coated with the intermediate layer.
  • step (b) of the process can be repeated several times.
  • step (c) of the process can be repeated several times.
  • the thickness of the intermediate layer generally represents between 2 and 60 g / m 2 of substrate and preferably between 20 and 35 g / m 2 .
  • the concentration of solution A is judiciously chosen so that this preferred thickness can be obtained by repeating step (b) in a reasonable number of times and preferably between 1 and 4 times.
  • the thickness of the outer layer represents between 5 and 70 g / m 2 of the substrate and preferably between 25 and 50 g / m 2 .
  • solution B is prepared so that its concentration makes it possible to obtain an outer layer thickness in the preferred range by repeating step (c) in less than 10 times and preferably between 2 and 5 times.
  • the specific cathode can be used in the preparation of an alkali metal chlorate by electrolysis of the corresponding chloride.
  • the specific cathode according to the invention is very particularly suitable for the preparation of sodium chlorate.
  • DSA Dissionally Stable Anode
  • anodes consisting of a titanium substrate coated with a layer of mixed titanium and ruthenium oxide.
  • the ruthenium / titanium molar ratio in this layer is advantageously between 0.4 and 2.4.
  • the following examples illustrate the invention without limiting it. 6 EXPERIMENTAL PART
  • a solution A is prepared, containing ruthenium and titanium in an equimolar amount, by mixing at room temperature with stirring 2.45 g of RuCI 3 , of purity greater than 98%, 3.64 cm 3 of TiOCI 2 , 2HCI at 1 27 g / l of Ti and 2.5 cm 3 of absolute isopropanol.
  • the end of one of the faces of the pretreated plate representing a surface of dimension 2 cm ⁇ 5 cm, is then coated with solution A using a brush, then it is left for 30 minutes at room temperature.
  • the coated plate is then dried for 30 minutes in an oven at 120 ° C, then calcined in an oven in air at 500 ° C for 30 minutes.
  • a zirconium, ruthenium and titanium precursor is mixed with stirring with absolute ethanol or water.
  • Solution B, thus formed, is cooled using an ice bath and is kept stirring until use.
  • the coated plate in (a) is then coated with solution B using a brush.
  • the coated plate is then dried for 30 minutes in an oven at 120 ° C., then calcined in an oven in air at 500 ° C. for 30 minutes. These operations are repeated (coating, drying and calcination) several times until an external layer representing between 30 and 45 g / m 2 of the plate is obtained.
  • the electrolytic solution (i) allows us to characterize the electrode by the value of the cathodic potential, E cat h, for a given current density.
  • the current-voltage curve obtained with the electrolytic solution (ii) has a current plateau between - 0.8 and -1.2 V / DHW. The value corresponding to this level is the limiting current for reduction of hypochlorite ions, i rec j.
  • Solution B is prepared by mixing, with stirring, in a container, cooled using an ice bath, 5.83 g of ZrCl4, 0.01 g of RuCI 3 , 2.74 cm 3 of TiCI 4 and 1 0 cm 3 of absolute ethanol.
  • the plate coated with the intermediate layer is then coated with the solution B thus prepared, then it is dried and calcined in air as indicated in the general procedure. These operations are repeated 4 times and at the end of the last calcination, the mass of the outer layer is 30 g / m 2 of the plate.
  • the cathode thus prepared was evaluated using the electrolytic solutions described above.
  • This Table also gives the value of the cathodic potential for a current density of 2KA / m 2 and the value of the limiting current for the different cathodes prepared according to the general operating mode but with 8 an outer layer composition, different from that used in Example 1.
  • a mild steel cathode (Example 8) and a titanium plate coated with the intermediate layer according to (I - a) (Example 9) were evaluated under the same conditions as the cathodes prepared according to the invention.
  • the cathodic potential was determined in the presence of the dichromate.
  • the plateau of the current-voltage curve observed with the electrolytic solution (ii), using the cathodes prepared according to the invention, is greatly attenuated or even nonexistent.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Automation & Control Theory (AREA)
  • Inorganic Chemistry (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to a specific cathode comprising a substrate made of an element chosen from the group formed by titanium, nickel, tantalum, zirconium, niobium and alloys thereof, the said substrate being coated with an interlayer of a mixed oxide based on titanium and on ruthenium and with an external layer of metal oxides comprising titanium, zirconium and ruthenium. The subject of the invention is also its manufacturing process and its applications in electrolysis.

Description

1 1
CATHODE SPECIFIQUE, UTILISABLE POUR LA PREPARATION D'UN CHLORATE DE METAL ALCALIN, ET SON PROCEDE DE FABRICATIONSPECIFIC CATHODE FOR USE IN THE PREPARATION OF AN ALKALINE METAL CHLORATE, AND METHOD FOR THE PRODUCTION THEREOF
La présente invention concerne une cathode, utilisable pour la préparation d 'un chlorate de métal alcalin par électrolyse du chlorure correspondant, et son procédé de fabrication.The present invention relates to a cathode which can be used for the preparation of an alkali metal chlorate by electrolysis of the corresponding chloride, and to the process for its production.
Si l'activation des cathodes pour la synthèse électrolytique du chlorate de sodium a fait l'objet de nombreux travaux, en revanche très peu d'études ont été consacrées à l'obtention des cathodes spécifiques. Or on sait que dans la préparation électrolytique du chlorate de sodium, parallèlement aux réactions conduisant au produit final, il existe de nombreuses réactions secondaires. Ainsi à la cathode, outre la réduction de l'eau en hydrogène, il se produit une réaction de réduction de l'ion hypochlorite.While the activation of cathodes for the electrolytic synthesis of sodium chlorate has been the subject of numerous studies, on the other hand very few studies have been devoted to obtaining specific cathodes. However, it is known that in the electrolytic preparation of sodium chlorate, in addition to the reactions leading to the final product, there are many side reactions. Thus at the cathode, in addition to the reduction of water to hydrogen, there takes place a reduction reaction of the hypochlorite ion.
Industriellement le chlorate de sodium est fabriqué dans des cellules électrolytiques, chacune d'elles comprenant plusieurs cathodes en acier doux et plusieurs anodes en titane revêtues d'oxyde de ruthénium. Elles sont en général alimentées en solution électrolytique constituée d'environ 1 00 g/l de chlorure de sodium, d'environ 600 g/l de chlorate de sodium et de bichromate de sodium en quantité comprise entre 2 et 5 g/l.Industrially, sodium chlorate is manufactured in electrolytic cells, each of which comprises several mild steel cathodes and several titanium anodes coated with ruthenium oxide. They are generally supplied with an electrolytic solution consisting of approximately 1 00 g / l of sodium chloride, approximately 600 g / l of sodium chlorate and sodium dichromate in an amount between 2 and 5 g / l.
Ce dernier étant utilisé pour réduire voire supprimer la réaction de réduction de l'ion hypochlorite. Malgré l'action importante qu'a le bichromate sur la réduction de l'ion hypochlorite et sa facilité d'emploi, le chrome (VI) est aujourd'hui menacé parce que le chlorate de métal alcalin ainsi préparé nécessite une étape de purification, mais surtout parce qu'il pollue l'environnement. Par conséquent, il apparaît capital dans un souci d'écologie de trouver une solution de remplacement.The latter being used to reduce or even suppress the reduction reaction of the hypochlorite ion. Despite the important action that dichromate has on the reduction of the hypochlorite ion and its ease of use, chromium (VI) is today threatened because the alkali metal chlorate thus prepared requires a purification step, but mainly because it pollutes the environment. Consequently, it appears essential in an ecological concern to find an alternative solution.
Ainsi le document US 4 295 951 propose d'utiliser une cathode dont le substrat en titane, fer ou alliage de titane est revêtu d' une couche protectrice non-conductrice, constituée d 'un film de polymères halogènes tels que le Téflon®Document US Pat. No. 4,295,951 therefore proposes using a cathode whose titanium, iron or titanium alloy substrate is coated with a non-conductive protective layer, consisting of a film of halogenated polymers such as Teflon®
Par ailleurs, une cathode dont le substrat est une plaque en titane, en zirconium, en niobium ou en alliage essentiellement constitué par une association de ces métaux et sur lequel est appliquée une couche d 'oxyde métallique, essentiellement constituée par un oxyde d' un ou plusieurs métaux choisis parmi le ruthénium, le rhodium, le palladium, l 'osmium, l'iridium et le platine et éventuellement un oxyde d'un ou plusieurs métaux choisis parmi le calcium, le magnésium, le strontium, le baryum, le zinc, le 2 chrome, le molybdène, le tungstène, le sélénium et le tellure, a été divulguée dans le brevet français FR 2 31 1 1 08.Furthermore, a cathode whose substrate is a plate of titanium, zirconium, niobium or an alloy essentially constituted by a combination of these metals and to which is applied a layer of metal oxide, essentially constituted by an oxide of a or several metals chosen from ruthenium, rhodium, palladium, osmium, iridium and platinum and optionally an oxide from one or more metals chosen from calcium, magnesium, strontium, barium, zinc , the 2 chromium, molybdenum, tungsten, selenium and tellurium, was disclosed in French patent FR 2 31 1 1 08.
Toutefois, d'après LINDBERGH et SIMONSON, Journal of Electrochemical Society, 1 990, vol. 1 37, N ° 1 0, p. 3094-3099, ces cathodes permettent seulement de réduire la cinétique de la réaction de réduction de l'ion hypochlorite et non de la supprimer.However, according to LINDBERGH and SIMONSON, Journal of Electrochemical Society, 1,990, vol. 1 37, N ° 1 0, p. 3094-3099, these cathodes only make it possible to reduce the kinetics of the reaction for reducing the hypochlorite ion and not to suppress it.
La société déposante a maintenant trouvé une cathode permettant d'inhiber la réaction de réduction de l'ion hypochlorite tout en conservant de bonnes propriétés vis à vis de la réaction de réduction de l'eau. Cette cathode spécifique comprend un substrat en un élément choisi dans le groupe formé de titane, nickel, tantale, zirconium, nobium et de leurs alliages, revêtu d'une couche intermédiaire d'oxyde mixte à base de titane et de ruthénium et d'une couche externe d'oxydes métalliques comprenant du titane, zirconium et ruthénium. Avantageusement, la couche intermédiaire contient un oxyde mixte de titane et de ruthénium.The applicant company has now found a cathode which makes it possible to inhibit the reduction reaction of the hypochlorite ion while retaining good properties with respect to the reaction for reducing water. This specific cathode comprises a substrate made of an element chosen from the group formed from titanium, nickel, tantalum, zirconium, nobium and their alloys, coated with an intermediate layer of mixed oxide based on titanium and ruthenium and a outer layer of metal oxides comprising titanium, zirconium and ruthenium. Advantageously, the intermediate layer contains a mixed oxide of titanium and ruthenium.
De préférence la couche externe d'oxydes métalliques contient du titane, du zirconium et du ruthénium.Preferably the outer layer of metal oxides contains titanium, zirconium and ruthenium.
Mieux encore, la couche externe est constituée essentiellement de ZrTiθ4 accompagné de Ruθ2 et éventuellement de Zrθ2 et/ou Tiθ2-Better still, the outer layer consists essentially of ZrTiθ4 accompanied by Ruθ2 and possibly Zrθ2 and / or Tiθ2-
Selon l'invention on préfère utiliser, comme substrat, le titane ou le nickel ou les alliages de titane ou de nickel. Mieux encore, on préfère utiliser le titane.According to the invention it is preferred to use, as substrate, titanium or nickel or titanium or nickel alloys. Even better, we prefer to use titanium.
Le ratio molaire ruthénium/titane dans la couche intermédiaire est de préférence compris entre 0,4 et 2,4.The ruthenium / titanium molar ratio in the intermediate layer is preferably between 0.4 and 2.4.
Le ratio molaire zirconium/titane dans la couche externe est généralement compris entre 0,25 et 9, de préférence compris entre 0,5 et 2.The zirconium / titanium molar ratio in the outer layer is generally between 0.25 and 9, preferably between 0.5 and 2.
Le ruthénium dans la couche externe représente entre 0, 1 et 1 0 % molaire, de préférence entre 0, 1 et 5 % molaire par rapport aux métaux entrant dans la composition de cette couche.The ruthenium in the outer layer represents between 0.1 and 10 mol%, preferably between 0.1 and 5 mol% relative to the metals used in the composition of this layer.
Un autre objet de l'invention est le procédé de préparation de la cathode spécifique, comprenant les étapes suivantes : a) prétraitement d'un substrat pour conférer des caractéristiques de rugosité à la surface, b) revêtement du substrat prétraité à l'aide d'une solution A contenant essentiellement du titane et du ruthénium, suivi de séchage, puis calcination du substrat ainsi revêtu, 3 c) revêtement du substrat obtenu en (b) à l'aide d'une solution B comprenant du titane, du zirconium et du ruthénium, suivi de séchage, et de la calcination du substrat.Another object of the invention is the process for preparing the specific cathode, comprising the following steps: a) pretreatment of a substrate to impart surface roughness characteristics, b) coating of the pretreated substrate using a solution A essentially containing titanium and ruthenium, followed by drying, then calcination of the substrate thus coated, C) coating of the substrate obtained in (b) using a solution B comprising titanium, zirconium and ruthenium, followed by drying, and calcination of the substrate.
Le prétraitement consiste en général à soumettre le substrat, soit à un sablage suivi d'un lavage à l'acide, soit à un décapage à l'aide d'une solution aqueuse d'acide oxalique, d'acide fluorhydrique, d'un mélange d'acide fluorhydrique et d'acide nitrique, d'un mélange d'acide fluorhydrique et de glycérol, d'un mélange d'acide fluorhydrique, d'acide nitrique et de glycérol ou d'un mélange d'acide fluorhydrique, d'acide nitrique et de peroxyde d'hydrogène, suivi d'un ou de plusieurs lavage(s) à l'eau déminéralisée dégazéifiée.The pretreatment generally consists in subjecting the substrate, either to a sandblasting followed by an acid washing, or to a pickling using an aqueous solution of oxalic acid, hydrofluoric acid, a mixture of hydrofluoric acid and nitric acid, mixture of hydrofluoric acid and glycerol, mixture of hydrofluoric acid, nitric acid and glycerol or mixture of hydrofluoric acid, d 'nitric acid and hydrogen peroxide, followed by one or more washing (s) with degassed demineralized water.
Le substrat peut être sous la forme de plaque massive, plaque perforée, métal déployé ou panier cathodique constitué à partir du métal déployé ou perforé. La solution A est en général préparée en faisant réagir à température ambiante et sous agitation, essentiellement un sel minéral ou organique de titane et de ruthénium avec de l'eau ou dans un solvant organique, éventuellement en présence d'un agent chelatant. La température peut être portée légèrement au dessus de l'ambiante pour faciliter la dissolution des sels.The substrate may be in the form of a solid plate, perforated plate, expanded metal or cathode basket made from the expanded or perforated metal. Solution A is generally prepared by reacting at room temperature and with stirring, essentially a mineral or organic salt of titanium and ruthenium with water or in an organic solvent, optionally in the presence of a chelating agent. The temperature can be brought slightly above the ambient to facilitate the dissolution of the salts.
Avantageusement on fait réagir un sel minéral ou organique de titane et de ruthénium avec de l'eau ou dans un solvant organique, éventuellement en présence d'un agent chelatant.Advantageously, a mineral or organic salt of titanium and ruthenium is reacted with water or in an organic solvent, optionally in the presence of a chelating agent.
Le titane et le ruthénium sont de préférence présents dans la solution A en une concentration équivalant à chacun de 0,5 à 1 0 mole/l.Titanium and ruthenium are preferably present in solution A in a concentration equivalent to each of 0.5 to 10 mole / l.
La solution B est en général préparée en faisant réagir, à température ambiante et sous agitation, un sel minéral ou organique de titane, de zirconium, de ruthénium et éventuellement d'autres métaux avec de l'eau ou dans un solvant organique, éventuellement en présence d'un agent chelatant. Lorsque la réaction est exothermique, on utilise un bain de glace pour refroidir le milieu réactionnel.Solution B is generally prepared by reacting, at room temperature and with stirring, an inorganic or organic salt of titanium, zirconium, ruthenium and optionally other metals with water or in an organic solvent, optionally in presence of a chelating agent. When the reaction is exothermic, an ice bath is used to cool the reaction medium.
Avantageusement, on fait réagir un sel minéral ou organique de titane, de zirconium et de ruthénium avec de l'eau ou dans un solvant organique, éventuellement en présence d'un agent chelatant. Les sels de titane et de ruthénium préférés sont les chlorures, les oxychlorures, les nitratres, les oxynitrates, les sulfates et les alkoxydes. Avantageusement les chlorures de ruthénium, les chlorures de titane et oxychlorures de titane sont utilisés. 4 Comme sels de zirconium, on peut utiliser les chlorures, les sulfates, le chlorures de zirconyle, le nitrates de zirconyle, les alkoxydes tels que le zirconate de butyle.Advantageously, a mineral or organic salt of titanium, zirconium and ruthenium is reacted with water or in an organic solvent, optionally in the presence of a chelating agent. The preferred titanium and ruthenium salts are chlorides, oxychlorides, nitraters, oxynitrates, sulfates and alkoxides. Advantageously ruthenium chlorides, titanium chlorides and titanium oxychlorides are used. As the zirconium salts, it is possible to use chlorides, sulfates, zirconyl chlorides, zirconyl nitrates, alkoxides such as butyl zirconate.
Les chlorures de zirconium et de zirconyle sont particulièrement préférés.Zirconium and zirconyl chlorides are particularly preferred.
Comme solvant organique, on peut citer les alcools légers de préférence l'isopropanol et l'éthanol, et mieux encore l'isopropanol et l'éthanol absolu.As organic solvent, there may be mentioned light alcohols, preferably isopropanol and ethanol, and better still isopropanol and absolute ethanol.
Bien que l'on puisse utiliser indifféremment de l'eau ou un solvant organique pour préparer la solution B, on préfère toutefois employer un solvant organique lorsque les sels métalliques sont solides à température ambiante.Although water or an organic solvent can be used indifferently to prepare solution B, it is however preferred to use an organic solvent when the metal salts are solid at room temperature.
Ainsi lorsque le sel métallique est le chlorure de zirconium, on utilise comme solvant l'éthanol absolu ou l'isopropanol absolu. Le titane et le zirconium sont en général présents dans la solutionThus, when the metal salt is zirconium chloride, absolute ethanol or absolute isopropanol is used as the solvent. Titanium and zirconium are generally present in the solution
B en une concentration équivalant à chacun de 0,5 à 5 mole/1. La concentration de ruthénium dans la solution B est généralement comprise entre 1 0~3 et 1 0~ 1 mole/l, de préférence comprise entre 1 0"3 et 5.1 0"2 mole/l. On peut déposer la solution A sur le substrat prétraité en utilisant différentes techniques telles que sol-gel, dépôt électrochimique, électrodéposition galvanique, pulvérisation ou enduction.B in a concentration equivalent to each of 0.5 to 5 mol / l. The concentration of ruthenium in solution B is generally between 1 0 ~ 3 and 1 0 ~ 1 mole / l, preferably between 1 0 "3 and 5.1 0 " 2 mole / l. Solution A can be deposited on the pretreated substrate using different techniques such as sol-gel, electrochemical deposition, galvanic plating, spraying or coating.
Avantageusement on enduit le substrat prétraité avec la solution A, par exemple à l'aide d'un pinceau. Le substrat ainsi revêtu est ensuite séché à l'air et/ou dans une étuve à une température inférieure à 1 50°C. Après le séchage, le substrat est calciné sous air à une température comprise entre 300 et 600°C et de préférence comprise entre 450 et 550°C pendant une durée allant de 1 0 minutes à 2 heures.Advantageously, the pretreated substrate is coated with solution A, for example using a brush. The substrate thus coated is then dried in air and / or in an oven at a temperature below 150 ° C. After drying, the substrate is calcined in air at a temperature between 300 and 600 ° C and preferably between 450 and 550 ° C for a period ranging from 10 minutes to 2 hours.
Pour l'étape (c) du procédé selon la présente invention, on peut utiliser les mêmes techniques de dépôt ainsi que les mêmes conditions opératoires de séchage et calcination que l'étape (b) sauf que le dépôt est effectué avec la solution B.For step (c) of the process according to the present invention, the same deposition techniques can be used as well as the same operating conditions for drying and calcination as step (b) except that the deposition is carried out with solution B.
D'autres techniques telles que dépôt chimique en phase vapeur (CVD), dépôt physique en phase vapeur (PVD), projection plasma, conviennent également pour le revêtement du substrat prétraité d'une couche intermédiaire et d'une couche externe.Other techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma spraying, are also suitable for coating the pretreated substrate with an intermediate layer and an outer layer.
On peut déposer la solution A aussi bien sur l'une des faces de substrat prétraité que sur les deux faces. On peut également déposer la 5 solution B sur les deux faces du substrat revêtu de la couche intermédiaire.Solution A can be deposited both on one side of the pretreated substrate and on both sides. You can also file the 5 solution B on both sides of the substrate coated with the intermediate layer.
Suivant l'épaisseur de la couche intermédiaire souhaitée on peut répéter plusieurs fois l'étape (b) du procédé. De même, on peut répéter plusieurs fois l'étape (c) du procédé.Depending on the thickness of the desired intermediate layer, step (b) of the process can be repeated several times. Likewise, step (c) of the process can be repeated several times.
L'épaisseur de la couche intermédiaire représente en générai entre 2 et 60 g/m2 de substrat et de préférence entre 20 et 35 g/m2.The thickness of the intermediate layer generally represents between 2 and 60 g / m 2 of substrate and preferably between 20 and 35 g / m 2 .
La concentration de la solution A est judicieusement choisie de manière à ce que cette épaisseur préférée puisse être obtenue en répétant l'étape (b) en un nombre de fois raisonnable et de préférence entre 1 et 4 fois.The concentration of solution A is judiciously chosen so that this preferred thickness can be obtained by repeating step (b) in a reasonable number of times and preferably between 1 and 4 times.
L'épaisseur de la couche externe représente entre 5 et 70 g/m2 du substrat et de préférence entre 25 et 50 g/m2. On prépare en général la solution B de manière à ce que sa concentration permette d'obtenir une épaisseur de couche externe dans la plage préférée en répétant en moins de 1 0 fois l'étape (c) et de préférence entre 2 et 5 fois.The thickness of the outer layer represents between 5 and 70 g / m 2 of the substrate and preferably between 25 and 50 g / m 2 . In general, solution B is prepared so that its concentration makes it possible to obtain an outer layer thickness in the preferred range by repeating step (c) in less than 10 times and preferably between 2 and 5 times.
Selon un autre objet de l'invention, la cathode spécifique peut être utilisée dans la préparation d'un chlorate de métal alcalin par électrolyse du chlorure correspondant. La cathode spécifique selon l'invention convient tout particulièrement à la préparation du chlorate de sodium.According to another object of the invention, the specific cathode can be used in the preparation of an alkali metal chlorate by electrolysis of the corresponding chloride. The specific cathode according to the invention is very particularly suitable for the preparation of sodium chlorate.
L'utilisation de la cathode spécifique en association avec une anode permet de synthétiser électrolytiquement le chlorate d'un métal alcalin avec un rendement Faraday élevé et en l'absence de bichromate de sodium.The use of the specific cathode in combination with an anode makes it possible to electrolytically synthesize the chlorate of an alkali metal with a high Faraday yield and in the absence of sodium dichromate.
On peut citer comme anode, les anodes DSA (Dimensionally Stable Anode) constituées d'un substrat en titane revêtu d'une couche d'oxyde mixte de titane et de ruthénium. Le rapport molaire ruthénium/titane dans cette couche est avantageusement compris entre 0,4 et 2,4. Les exemples suivants illustrent l'invention sans la limiter. 6 PARTIE EXPERIMENTALEAs anode, mention may be made of DSA (Dimensionally Stable Anode) anodes consisting of a titanium substrate coated with a layer of mixed titanium and ruthenium oxide. The ruthenium / titanium molar ratio in this layer is advantageously between 0.4 and 2.4. The following examples illustrate the invention without limiting it. 6 EXPERIMENTAL PART
I - Préparation de la cathode a) Prétraitement et dépôt de la couche intermédiaire On sable une plaque de titane d'une épaisseur de 2 mm et de dimensions 2 cm x 1 5 cm, et on la rince ensuite avec une solution d'acide chlorhydrique dilué pour enlever toutes traces de pollution.I - Preparation of the cathode a) Pretreatment and deposition of the intermediate layer A titanium plate 2 mm thick and 2 cm × 15 cm in size is sanded, and then rinsed with a hydrochloric acid solution diluted to remove all traces of pollution.
On prépare une solution A, contenant du ruthénium et du titane en quantité équimolaire, en mélangeant à température ambiante sous agitation 2,45 g de RuCI3, de pureté supérieure à 98 %, 3,64 cm3 de TiOCI2, 2HCI à 1 27 g/l en Ti et 2,5 cm3 d'isopropanol absolu.A solution A is prepared, containing ruthenium and titanium in an equimolar amount, by mixing at room temperature with stirring 2.45 g of RuCI 3 , of purity greater than 98%, 3.64 cm 3 of TiOCI 2 , 2HCI at 1 27 g / l of Ti and 2.5 cm 3 of absolute isopropanol.
On enduit ensuite l'extrémité d'une des faces de la plaque prétraitée, représentant une surface de dimension 2 cm x 5 cm, avec la solution A à l'aide d'un pinceau, puis on la laisse 30 minutes à température ambiante. La plaque enduite est ensuite séchée pendant 30 minutes dans une étuve à 1 20°C, puis calcinée dans un four sous air à 500°C pendant 30 minutes.The end of one of the faces of the pretreated plate, representing a surface of dimension 2 cm × 5 cm, is then coated with solution A using a brush, then it is left for 30 minutes at room temperature. The coated plate is then dried for 30 minutes in an oven at 120 ° C, then calcined in an oven in air at 500 ° C for 30 minutes.
On répète ces opérations (enduction, séchage et calcination) encore 3 fois et au bout de ces 4 enductions, on obtient une couche d'oxyde mixte Ru-Ti représentant environ 30 g/m2 de la plaque. b) Dépôt de la couche externeThese operations are repeated (coating, drying and calcination) 3 more times and at the end of these 4 coatings, a layer of mixed oxide Ru-Ti is obtained representing approximately 30 g / m 2 of the plate. b) Deposition of the outer layer
Mode opératoire généralGeneral procedure
On mélange sous agitation un précurseur de zirconium, de ruthénium et de titane avec de l'éthanol absolu ou de l'eau. La solution B, ainsi formée, est refroidie à l'aide d'un bain de glace et est maintenue sous agitation jusqu'à son utilisation.A zirconium, ruthenium and titanium precursor is mixed with stirring with absolute ethanol or water. Solution B, thus formed, is cooled using an ice bath and is kept stirring until use.
On enduit ensuite, la plaque revêtue en (a), avec la solution B à l'aide d'un pinceau. La plaque enduite est ensuite séchée pendant 30 minutes dans une étuve à 1 20°C, puis calcinée dans un four sous air à 500°C pendant 30 minutes. On répète ces opérations (enduction, séchage et calcination) plusieurs fois jusqu'à l'obtention d'une couche externe représentant entre 30 et 45 g/m2 de la plaque.The coated plate in (a) is then coated with solution B using a brush. The coated plate is then dried for 30 minutes in an oven at 120 ° C., then calcined in an oven in air at 500 ° C. for 30 minutes. These operations are repeated (coating, drying and calcination) several times until an external layer representing between 30 and 45 g / m 2 of the plate is obtained.
II - Evaluation de la cathodeII - Evaluation of the cathode
On utilise trois solutions électrolytiques suivantes pour évaluer la cathode spécifique ainsi préparée :The following three electrolytic solutions are used to evaluate the specific cathode thus prepared:
(i) une solution de NaOH 1 N à 25 °C pour étudier le dégagement d'hydrogène, 7 (ii) une solution de NaOH 1 N à 25 °C contenant 5g/l de NaCIO pour étudier la réduction de l'ion hypochlorite, et(i) a 1 N NaOH solution at 25 ° C to study the evolution of hydrogen, 7 (ii) a 1 N NaOH solution at 25 ° C. containing 5 g / l of NaCIO to study the reduction of the hypochlorite ion, and
(iii) une solution de NaOH 1 N à 25 °C contenant 5g/l de NaCIO et 5 g/l de Na2Cr207, 2H2O pour étudier la suppression de la réduction de l'ion hypochlorite par l'action du bichromate.(iii) a 1 N NaOH solution at 25 ° C. containing 5 g / l of NaCIO and 5 g / l of Na2Cr 2 0 7 , 2H 2 O to study the suppression of the reduction of the hypochlorite ion by the action of bichromate.
En utilisant une électrode de référence au calomel saturé, ECS, la solution électrolytique (i) nous permet de caractériser l'électrode par la valeur du potentiel cathodique, Ecath, pour une densité de courant donnée. La courbe courant-tension obtenue avec la solution électrolytique (ii) présente un palier en courant entre - 0,8 et -1 ,2 V/ECS. La valeur correspondant à ce palier est le courant limite de réduction des ions hypochlorite, irecj.By using a saturated calomel reference electrode, ECS, the electrolytic solution (i) allows us to characterize the electrode by the value of the cathodic potential, E cat h, for a given current density. The current-voltage curve obtained with the electrolytic solution (ii) has a current plateau between - 0.8 and -1.2 V / DHW. The value corresponding to this level is the limiting current for reduction of hypochlorite ions, i rec j.
La courbe courant-tension enregistrée lors de l'évaluation des cathodes avec la solution électrolytique (iii) nous donne le courant limite de réduction des ions hypochlorite en présence de bichromate de sodium, irecl (Cr), par mesure du courant résiduel entre -0,8 et -1 ,2 V/ECS. III - Exemples Exemple 1The current-voltage curve recorded during the evaluation of the cathodes with the electrolytic solution (iii) gives us the limiting current for reduction of hypochlorite ions in the presence of sodium dichromate, i rec l (Cr), by measuring the residual current between -0.8 and -1.2 V / DHW. III - Examples Example 1
On prépare la solution B en mélangeant sous agitation dans un récipient, refroidi à l'aide d'un bain de glace, 5,83 g de ZrCl4, 0,01 g de RuCI3, 2,74 cm3 de TiCI4 et 1 0 cm3 d'éthanol absolu.Solution B is prepared by mixing, with stirring, in a container, cooled using an ice bath, 5.83 g of ZrCl4, 0.01 g of RuCI 3 , 2.74 cm 3 of TiCI 4 and 1 0 cm 3 of absolute ethanol.
On enduit ensuite, la plaque revêtue de la couche intermédiaire, avec la solution B ainsi préparée, puis on la sèche et la calcine sous air comme indiqué dans le mode opératoire général. Ces opérations sont répétées 4 fois et à l'issue de la dernière calcination, la masse de couche externe est de 30 g/m2 de la plaque.The plate coated with the intermediate layer is then coated with the solution B thus prepared, then it is dried and calcined in air as indicated in the general procedure. These operations are repeated 4 times and at the end of the last calcination, the mass of the outer layer is 30 g / m 2 of the plate.
La cathode, ainsi préparée a été évaluée à l'aide des solutions électrolytiques décrites précédemment.The cathode thus prepared was evaluated using the electrolytic solutions described above.
L'étude du dégagement d'hydrogène donne une valeur du potentiel cathodique Ecath = -1 ,28 V/ECS pour une densité de courant de 2 KA/m2 (20 A/dm2).The study of the evolution of hydrogen gives a value of the cathode potential E cath = -1, 28 V / DHW for a current density of 2 KA / m 2 (20 A / dm 2 ).
La valeur du courant limite de réduction des ions hypochlorite en présence et en l'absence du bichromate sont reportées dans le tableau ci- après. Exemples 2-7The value of the limiting reduction current of the hypochlorite ions in the presence and in the absence of the dichromate are given in the table below. Examples 2-7
Ce Tableau donne également la valeur du potentiel cathodique pour une densité de courant de 2KA/m2 et la valeur du courant limite pour les différentes cathodes préparées selon le mode opératoire général mais avec 8 une composition de couche externe, différente de celle utilisée dans l'exemple 1 .This Table also gives the value of the cathodic potential for a current density of 2KA / m 2 and the value of the limiting current for the different cathodes prepared according to the general operating mode but with 8 an outer layer composition, different from that used in Example 1.
Exemples 8 et 9 comparatifsComparative examples 8 and 9
Une cathode en acier doux (exemple 8) et une plaque en titane revêtu de la couche intermédiaire selon (I - a) (exemple 9) ont été évaluées dans les mêmes conditions que les cathodes préparées selon l'invention.A mild steel cathode (Example 8) and a titanium plate coated with the intermediate layer according to (I - a) (Example 9) were evaluated under the same conditions as the cathodes prepared according to the invention.
Pour l'exemple 8, le potentiel cathodique a été déterminé en présence du bichromate.For example 8, the cathodic potential was determined in the presence of the dichromate.
Contrairement aux cathodes selon les exemples 8 et 9, le palier de la courbe courant-tension observée avec la solution électrolytique (ii), en utilisant les cathodes préparées selon l'invention, est fortement atténué voire inexistant. Unlike the cathodes according to Examples 8 and 9, the plateau of the current-voltage curve observed with the electrolytic solution (ii), using the cathodes prepared according to the invention, is greatly attenuated or even nonexistent.
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Claims

10 R E V E N D I C A T I O N S 10 CLAIMS
1 . Cathode comprenant un substrat en titane, nickel, tantale, zirconium ou nobium ou leurs alliages, une couche intermédiaire d'oxyde mixte à base de titane et de ruthénium et une couche externe d'oxydes métalliques comprenant du titane, zirconium et ruthénium.1. Cathode comprising a substrate made of titanium, nickel, tantalum, zirconium or nobium or their alloys, an intermediate layer of mixed oxide based on titanium and ruthenium and an external layer of metal oxides comprising titanium, zirconium and ruthenium.
2. Cathode selon la revendication 1 caractérisée en ce que le substrat est en nickel ou titane ou en alliages de nickel ou titane.2. Cathode according to claim 1 characterized in that the substrate is nickel or titanium or nickel or titanium alloys.
3. Cathode selon la revendication 2 caractérisée en ce que le substrat est en titane. 3. Cathode according to claim 2 characterized in that the substrate is made of titanium.
4. Cathode selon l'une des revendications 1 à 3 caractérisée en ce que la couche intermédiaire est un oxyde mixte de titane et de ruthénium. 4. Cathode according to one of claims 1 to 3 characterized in that the intermediate layer is a mixed oxide of titanium and ruthenium.
5. Cathode selon l'une des revendications 1 à 4 caractérisée en ce que la couche externe d'oxydes métalliques contient du titane, du zirconium et du ruthénium. 5. Cathode according to one of claims 1 to 4 characterized in that the outer layer of metal oxides contains titanium, zirconium and ruthenium.
6. Cathode selon la revendication 5 caractérisée en ce que la couche est externe est constituée essentiellement de ZrTi04 accompagné de Ru02 et éventuellement de Zr02 et /ou Ti0 .6. Cathode according to claim 5 characterized in that the layer is external consists essentially of ZrTi0 4 accompanied by Ru0 2 and optionally Zr0 2 and / or Ti0.
7. Cathode selon l'une des revendications 1 à 6 caractérisée en ce que le rapport molaire ruthénium/titane dans la couche intermédiaire est compris entre 0,4 et 2,4.7. Cathode according to one of claims 1 to 6 characterized in that the ruthenium / titanium molar ratio in the intermediate layer is between 0.4 and 2.4.
8. Cathode selon l'une des revendications 1 à 7 caractérisée en ce que le rapport molaire zirconium/titane dans la couche externe est compris entre 0,25 et 9.8. Cathode according to one of claims 1 to 7 characterized in that the zirconium / titanium molar ratio in the outer layer is between 0.25 and 9.
9. Cathode selon la revendication 8 caractérisée en ce que le rapport molaire zirconium/titane est compris entre 0,5 et 2.9. Cathode according to claim 8 characterized in that the zirconium / titanium molar ratio is between 0.5 and 2.
1 0. Cathode selon l'une des revendications 1 à 9 caractérisée en ce que le ruthénium dans la couche externe représente entre 0, 1 et 1 0 % molaire par rapport aux métaux entrant dans la composition de cette couche. 1 0. Cathode according to one of claims 1 to 9 characterized in that the ruthenium in the outer layer represents between 0, 1 and 1 0 mol% relative to the metals used in the composition of this layer.
1 1 . Cathode selon la revendication 1 0 caractérisée en ce que les ruthénium dans la couche externe représente entre 0, 1 et 5 % molaire.1 1. Cathode according to Claim 1 0, characterized in that the ruthenium in the outer layer represents between 0.1 and 5 mol%.
1 2. Procédé d'obtention d 'une cathode selon l 'une des revendications 1 à 1 1 comprenant les étapes suivantes : a) prétraitement du substrat, b) revêtement du substrat prétraité, à l'aide d'une solution A contenant essentiellement du titane et du ruthénium, suivi de séchage, puis calcination, 1 1 c) revêtement du substrat obtenu en (b), à l'aide d'une solution B comprenant du titane, du zirconium et ruthénium, suivi de séchage et de calcination.1 2. Method for obtaining a cathode according to one of claims 1 to 1 1 comprising the following steps: a) pretreatment of the substrate, b) coating of the pretreated substrate, using a solution A containing essentially titanium and ruthenium, followed by drying, then calcination, 1 1 c) coating of the substrate obtained in (b), using a solution B comprising titanium, zirconium and ruthenium, followed by drying and calcination.
1 3. Procédé selon la revendication 1 2 caractérisé en ce que le séchage de l'étape (b) et/ou (c) est (sont) effectué(s) à l'air et/ou dans une étuve à une température inférieure à 1 50°C.1 3. Method according to claim 1 2 characterized in that the drying of step (b) and / or (c) is (are) carried out (s) in air and / or in an oven at a lower temperature at 150 ° C.
1 4. Procédé selon la revendication 1 2 ou 1 3 caractérisé en ce que la calcination de l'étape (b) et/ou (c) est (sont) effectuée(s) sous air à une température comprise entre 300 et 600°C. 1 4. Method according to claim 1 2 or 1 3 characterized in that the calcination of step (b) and / or (c) is (are) carried out in air at a temperature between 300 and 600 ° vs.
1 5. Procédé selon la revendication 1 4 caractérisé en ce que la température de calcination est comprise entre 450 et 550°C.1 5. Method according to claim 1 4 characterized in that the calcination temperature is between 450 and 550 ° C.
1 6. Procédé selon l'une des revendications 1 2 à 1 5 caractérisé en ce que l'étape (b) et/ou l'étape (c) peut (peuvent) être répétée(s).1 6. Method according to one of claims 1 2 to 1 5 characterized in that step (b) and / or step (c) can (can) be repeated (s).
1 7. Utilisation d'une cathode selon l'une des revendications 1 à 1 1 pour fabriquer electrolytiquement le chlorate d'un métal alcalin à partir du chlorure correspondant.1 7. Use of a cathode according to one of claims 1 to 1 1 for electrolytically manufacturing the chlorate of an alkali metal from the corresponding chloride.
1 8. Procédé de fabrication d'un chlorate de métal alcalin par électrolyse du chlorure correspondant à l'aide d'une cathode selon l'une des revendications 1 à 1 1 . 1 8. A method of manufacturing an alkali metal chlorate by electrolysis of the corresponding chloride using a cathode according to one of claims 1 to 1 1.
EP99903733A 1998-03-02 1999-02-11 Specific cathode, used for preparing an alkaline metal chlorate and method for making same Expired - Lifetime EP1060296B1 (en)

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FR2797646B1 (en) * 1999-08-20 2002-07-05 Atofina CATHODE FOR USE IN THE ELECTROLYSIS OF AQUEOUS SOLUTIONS
US20070007146A1 (en) * 2005-07-07 2007-01-11 Severn Trent Water Purification, Inc. Process for producing hypochlorite
TW201012973A (en) * 2008-09-30 2010-04-01 Industrie De Nora Spa Cathode member and bipolar plate for hypochlorite cells
WO2010119679A1 (en) * 2009-04-15 2010-10-21 パナソニック株式会社 Hydrogen generating device
WO2010130546A1 (en) * 2009-05-15 2010-11-18 Akzo Nobel Chemicals International B.V. Activation of cathode
ITMI20091621A1 (en) * 2009-09-23 2011-03-24 Industrie De Nora Spa ELECTRODE FOR ELECTROLYTIC PROCESSES WITH CONTROLLED CRYSTALLINE STRUCTURE
CN102029152B (en) * 2010-11-30 2012-12-26 福州大学 Ru-Zr-Ti ternary oxide active material and preparation method thereof
CN102719859A (en) * 2012-07-07 2012-10-10 西安泰金工业电化学技术有限公司 Titanium mesh anode for electrodeposited nickel and preparing method thereof
KR102260891B1 (en) * 2016-11-29 2021-06-07 주식회사 엘지화학 Electrode for electrolysis and preparing method for electrode for electrolysis
CN107488865A (en) * 2017-08-22 2017-12-19 安徽唯达水处理技术装备有限公司 A kind of cathode electrode coating of hypochlorite generator
IT201800003533A1 (en) * 2018-03-14 2019-09-14 Industrie De Nora Spa ELECTRODE FOR ELECTROCHLORATION PROCESSES
US11668017B2 (en) 2018-07-30 2023-06-06 Water Star, Inc. Current reversal tolerant multilayer material, method of making the same, use as an electrode, and use in electrochemical processes

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5137877A (en) * 1974-09-27 1976-03-30 Asahi Chemical Ind Denkaiyodenkyoku oyobi sonoseizoho
US4075070A (en) * 1976-06-09 1978-02-21 Ppg Industries, Inc. Electrode material
US4100049A (en) * 1977-07-11 1978-07-11 Diamond Shamrock Corporation Coated cathode for electrolysis cells
US4530742A (en) * 1983-01-26 1985-07-23 Ppg Industries, Inc. Electrode and method of preparing same
IL73536A (en) * 1984-09-13 1987-12-20 Eltech Systems Corp Composite catalytic material particularly for electrolysis electrodes,its manufacture and its use in electrolysis
US4589969A (en) * 1984-10-12 1986-05-20 Yurkov Leonid I Electrode for electrolysis of solutions of electrolytes and process for producing same
MX169643B (en) * 1985-04-12 1993-07-16 Oronzio De Nora Impianti ELECTRODE FOR ELECTROCHEMICAL PROCESSES, PROCEDURE FOR ITS PRODUCTION AND ELECTROLYSIS TANK CONTAINING SUCH ELECTRODE
FR2583781A1 (en) * 1985-06-24 1986-12-26 Atochem CATHODE FOR ELECTROLYSIS AND METHOD FOR MANUFACTURING THE SAME CATHODE
FR2596776B1 (en) * 1986-04-03 1988-06-03 Atochem CATHODE FOR ELECTROLYSIS AND A METHOD FOR MANUFACTURING SAID CATHODE
US5314601A (en) * 1989-06-30 1994-05-24 Eltech Systems Corporation Electrodes of improved service life
US5017276A (en) * 1989-12-26 1991-05-21 Chemetics International Company Ltd. Metal electrodes for electrochemical processes
GB9316926D0 (en) * 1993-08-13 1993-09-29 Ici Plc Electrode
US5503663A (en) * 1994-11-30 1996-04-02 The Dow Chemical Company Sable coating solutions for coating valve metal anodes
GB9502665D0 (en) * 1995-02-11 1995-03-29 Ici Plc Cathode for use in electrolytic cell
US5855751A (en) * 1995-05-30 1999-01-05 Council Of Scientific And Industrial Research Cathode useful for the electrolysis of aqueous alkali metal halide solution
US6217729B1 (en) * 1999-04-08 2001-04-17 United States Filter Corporation Anode formulation and methods of manufacture

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9945175A1 *

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NZ506471A (en) 2003-03-28
CA2322690C (en) 2009-06-09
ID27559A (en) 2001-04-12
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EP1060296B1 (en) 2001-09-05
DE69900266D1 (en) 2001-10-11
CN1291242A (en) 2001-04-11
AU2428899A (en) 1999-09-20
PL193623B1 (en) 2007-02-28
AU741267B2 (en) 2001-11-29
WO1999045175A1 (en) 1999-09-10
ATE205264T1 (en) 2001-09-15
NO322407B1 (en) 2006-10-02
CA2322690A1 (en) 1999-09-10
US6352625B1 (en) 2002-03-05
PL342190A1 (en) 2001-05-21
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JP2002506120A (en) 2002-02-26
BR9908390A (en) 2000-10-31
MXPA00008615A (en) 2002-04-24
NO20004332L (en) 2000-10-25
NO20004332D0 (en) 2000-08-31
ES2163931T3 (en) 2002-02-01
IL137167A0 (en) 2001-07-24
FR2775486A1 (en) 1999-09-03
PT1060296E (en) 2002-01-30
JP4279457B2 (en) 2009-06-17
TW580524B (en) 2004-03-21
IL137167A (en) 2003-10-31
FR2775486B1 (en) 2000-04-07
EA200000889A1 (en) 2001-02-26
KR20010041499A (en) 2001-05-25
BR9908390B1 (en) 2010-05-18
EA002200B1 (en) 2002-02-28
ZA991628B (en) 1999-09-02

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